Component for a turbine engine with a cooling hole

ABSTRACT

An apparatus and method relating to a cooling hole of a component of a turbine engine. The component can include a wall separating the hot gas fluid flow from the cooling fluid flow and having a heated surface along which the hot gas fluid flow flows and a cooled surface facing the cooling fluid flow and at least one cooling hole comprising at least one inlet at the cooled surface, at least one outlet at the heated surface, with the outlet having a modified outlet shape.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.16/249,285 filed Jan. 16, 2019, now U.S. Pat. No. 10,822,958 which isincorporated herein in its entirety.

BACKGROUND OF THE INVENTION

Turbine engines, and particularly gas or combustion turbine engines, arerotary engines that extract energy from a flow of combusted gasespassing through the engine onto a multitude of rotating turbine blades.

Engine efficiency increases with temperature of combustion gases.However, the combustion gases heat the various components along theirflow path, which in turn requires cooling thereof to achieve a longengine lifetime. Typically, the hot gas path components are cooled bybleeding air from the compressor. This cooling process reduces engineefficiency, as the bled air is not used in the combustion process.

Turbine engine cooling art is mature and is applied to various aspectsof cooling circuits and features in the various hot gas path components.For example, the combustor includes radially outer and inner liners,which require cooling during operation. Turbine nozzles include hollowvanes supported between outer and inner bands, which also requirecooling. Turbine rotor blades are hollow and typically include coolingcircuits therein, with the blades being surrounded by turbine shrouds,which also require cooling. The hot combustion gases are dischargedthrough an exhaust which may also be lined, and suitably cooled.

In all of these exemplary turbine engine components, thin metal walls ofhigh strength superalloy metals are typically used for enhanceddurability while minimizing the need for cooling thereof. Variouscooling circuits and features are tailored for these individualcomponents in their corresponding environments in the engine. Thesecomponents typically include common rows of film cooling holes.

A typical film cooling hole is a cylindrical bore for discharging a filmof cooling air along the external surface of the wall to provide thermalinsulation against the flow from hot combustion gases during operation.A coating, for example a thermal barrier coating, can be applied toportions of the cooling hole to prevent damage. The coating cancontribute to an undesirable stream away from the heated wall ratherthan along the heated wall, which can lead to flow separation and a lossof the film cooling effectiveness. The geometrical relationship betweenthe coating and the cooling hole can affect engine efficiency andairfoil cooling.

BRIEF DESCRIPTION OF THE INVENTION

In one aspect the disclosure relates to a component for a turbine enginewhich generates a hot gas fluid flow, and provides a cooling fluid flow,comprising a wall separating the hot gas fluid flow from the coolingfluid flow and having a heated surface along which the hot gas fluidflow flows and a cooled surface facing the cooling fluid flow; a set ofcooling holes comprising at least a first cooling hole and a secondcooling hole, each of the first and second cooling holes comprising afirst inlet and a second inlet, each located at the cooled surface, anda first outlet and a second outlet each located at the heated surface,with the first and second outlets each defining a modified outlet shapehaving: an expansion section having an increasing width, and a constantsection downstream of the expansion section and having a constant width,wherein the second inlet at the cooled surface is formed interiorly ofthe first outlet at the heated surface.

In yet another aspect, the disclosure relates to a component for amethod for forming a set of cooling holes for an engine component, theset of cooling holes including a first cooling hole extending between afirst inlet and a first outlet and a second cooling hole extendingbetween a second inlet and a second outlet, the method comprisingforming the set of cooling holes such that the first and second inletsare located on a first surface and the first and second outlets arelocated on a second surface and a geometric center of the first outletis in line with a geometric center of the first inlet; forming aconnecting passage to connect each of the first and second inlets to thecorresponding first and second outlets; and forming the first and secondoutlets each with a modified outlet shape, the modified outlet shapecomprising an expansion section having an increasing width, and aconstant section having a constant width and located downstream from theexpansion section.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:

FIG. 1 is a schematic cross-sectional diagram of a turbine engine for anaircraft.

FIG. 2 is an isometric view of an airfoil for the turbine engine of FIG.1 in the form of a blade and having multiple sets of cooling holes.

FIG. 3 is an enlarged view of one of the multiple sets of cooling holeslocated on a platform.

FIG. 4 is a top down perspective of a single cooling hole from the setof cooling holes of FIG. 3 showing an outlet shape according to anaspect of the disclosure herein.

FIG. 5 is a cross-sectional view of the single cooling hole from FIG. 4.

FIG. 6 is a top down perspective of an arrangement of multiple coolingholes with the outlet shape of FIG. 5 .

FIG. 7 is a cross-sectional view of a variation of the single coolinghole from FIG. 4 .

FIG. 8 is a top down perspective of a single cooling hole showing anoutlet shape according to another aspect of the disclosure herein.

FIG. 9 is a top down perspective of an arrangement of multiple coolingholes with the outlet shape of FIG. 8 .

DESCRIPTION OF EMBODIMENTS OF THE INVENTION

Aspects of the disclosure described herein are directed to the formationof a cooling hole in a wall of an engine component such as an airfoil,or the platform to which an airfoil is mounted. For purposes ofillustration, the aspects of the disclosure discussed herein will bedescribed with respect to the platform portion of a blade. It will beunderstood, however, that the disclosure as discussed herein is not solimited and may have general applicability within an engine, includingcompressors, as well as in non-aircraft applications, such as othermobile applications and non-mobile industrial, commercial, andresidential applications.

As used herein, the term “forward” or “upstream” refers to moving in adirection toward the engine inlet, or a component being relativelycloser to the engine inlet as compared to another component. The term“aft” or “downstream” used in conjunction with “forward” or “upstream”refers to a direction toward the rear or outlet of the engine relativeto the engine centerline. Additionally, as used herein, the terms“radial” or “radially” refer to a dimension extending between a centerlongitudinal axis of the engine and an outer engine circumference.Furthermore, as used herein, the term “set” or a “set” of elements canbe any number of elements, including only one.

All directional references (e.g., radial, axial, proximal, distal,upper, lower, upward, downward, left, right, lateral, front, back, top,bottom, above, below, vertical, horizontal, clockwise, counterclockwise,upstream, downstream, aft, etc.) are only used for identificationpurposes to aid the reader's understanding of the present disclosure,and do not create limitations, particularly as to the position,orientation, or use of the disclosure. Connection references (e.g.,attached, coupled, connected, and joined) are to be construed broadlyand can include intermediate members between a collection of elementsand relative movement between elements unless otherwise indicated. Assuch, connection references do not necessarily infer that two elementsare directly connected and in fixed relation to one another. Furthermoreit should be understood that the term cross section or cross-sectionalas used herein is referring to a section taken orthogonal to thecenterline and to the general coolant flow direction in the hole. Theexemplary drawings are for purposes of illustration only and thedimensions, positions, order and relative sizes reflected in thedrawings attached hereto can vary.

Referring to FIG. 1 , an engine 10 has a generally longitudinallyextending axis or centerline 12 extending forward 14 to aft 16. Theengine 10 includes, in downstream serial flow relationship, a fansection 18 including a fan 20, a compressor section 22 including abooster or low pressure (LP) compressor 24 and a high pressure (HP)compressor 26, a combustion section 28 including a combustor 30, aturbine section 32 including a HP turbine 34, and a LP turbine 36, andan exhaust section 38.

The fan section 18 includes a fan casing 40 surrounding the fan 20. Thefan 20 includes a plurality of fan blades 42 disposed radially about thecenterline 12. The HP compressor 26, the combustor 30, and the HPturbine 34 form a core 44 of the engine 10, which generates combustiongases. The core 44 is surrounded by core casing 46, which can be coupledwith the fan casing 40.

A HP shaft or spool 48 disposed coaxially about the centerline 12 of theengine 10 drivingly connects the HP turbine 34 to the HP compressor 26.A LP shaft or spool 50, which is disposed coaxially about the centerline12 of the engine 10 within the larger diameter annular HP spool 48,drivingly connects the LP turbine 36 to the LP compressor 24 and fan 20.The spools 48, 50 are rotatable about the engine centerline and coupleto a plurality of rotatable elements, which can collectively define arotor 51.

The LP compressor 24 and the HP compressor 26 respectively include aplurality of compressor stages 52, 54, in which a set of compressorblades 56, 58 rotate relative to a corresponding set of staticcompressor vanes 60, 62 (also called a nozzle) to compress or pressurizethe stream of fluid passing through the stage. In a single compressorstage 52, 54, multiple compressor blades 56, 58 can be provided in aring and can extend radially outwardly relative to the centerline 12,from a blade platform to a blade tip, while the corresponding staticcompressor vanes 60, 62 are positioned upstream of and adjacent to therotating blades 56, 58. It is noted that the number of blades, vanes,and compressor stages shown in FIG. 1 were selected for illustrativepurposes only, and that other numbers are possible.

The blades 56, 58 for a stage of the compressor mount to a disk 61,which mounts to the corresponding one of the HP and LP spools 48, 50,with each stage having its own disk 61. The vanes 60, 62 for a stage ofthe compressor mount to the core casing 46 in a circumferentialarrangement.

The HP turbine 34 and the LP turbine 36 respectively include a pluralityof turbine stages 64, 66, in which a set of turbine blades 68, 70 arerotated relative to a corresponding set of static turbine vanes 72, 74(also called a nozzle) to extract energy from the stream of fluidpassing through the stage. In a single turbine stage 64, 66, multipleturbine blades 68, 70 can be provided in a ring and can extend radiallyoutwardly relative to the centerline 12, from a blade platform to ablade tip, while the corresponding static turbine vanes 72, 74 arepositioned upstream of and adjacent to the rotating blades 68, 70. It isnoted that the number of blades, vanes, and turbine stages shown in FIG.1 were selected for illustrative purposes only, and that other numbersare possible.

The blades 68, 70 for a stage of the turbine can mount to a disk 71,which is mounts to the corresponding one of the HP and LP spools 48, 50,with each stage having a dedicated disk 71. The vanes 72, 74 for a stageof the compressor can mount to the core casing 46 in a circumferentialarrangement.

Complementary to the rotor portion, the stationary portions of theengine 10, such as the static vanes 60, 62, 72, 74 among the compressorand turbine section 22, 32 are also referred to individually orcollectively as a stator 63. As such, the stator 63 can refer to thecombination of non-rotating elements throughout the engine 10.

In operation, the airflow exiting the fan section 18 splits such that aportion of the airflow is channeled into the LP compressor 24, whichthen supplies pressurized air 76 to the HP compressor 26, which furtherpressurizes the air. The pressurized air 76 from the HP compressor 26mixes with fuel in the combustor 30 where the fuel combusts, therebygenerating combustion gases. The HP turbine 34 extracts some work fromthese gases, which drives the HP compressor 26. The HP turbine 34discharges the combustion gases into the LP turbine 36, which extractsadditional work to drive the LP compressor 24, and the exhaust gas isultimately discharged from the engine 10 via the exhaust section 38. Thedriving of the LP turbine 36 drives the LP spool 50 to rotate the fan 20and the LP compressor 24.

A portion of the pressurized airflow 76 can be drawn from the compressorsection 22 as bleed air 77. The bleed air 77 can be drawn from thepressurized airflow 76 and provided to engine components requiringcooling. The temperature of pressurized airflow 76 entering thecombustor 30 is significantly increased. As such, cooling provided bythe bleed air 77 is necessary for operating of such engine components inthe heightened temperature environments.

A remaining portion of the airflow 78 bypasses the LP compressor 24 andengine core 44 and exits the engine 10 through a stationary vane row,and more particularly an outlet guide vane assembly 80, comprising aplurality of airfoil guide vanes 82, at the fan exhaust side 84. Morespecifically, a circumferential row of radially extending airfoil guidevanes 82 are utilized adjacent the fan section 18 to exert somedirectional control of the airflow 78.

Some of the air supplied by the fan 20 can bypass the engine core 44 andbe used for cooling of portions, especially hot portions, of the engine10, and/or used to cool or power other aspects of the aircraft. In thecontext of a turbine engine, the hot portions of the engine are normallydownstream of the combustor 30, especially the turbine section 32, withthe HP turbine 34 being the hottest portion as it is directly downstreamof the combustion section 28. Other sources of cooling fluid can be, butare not limited to, fluid discharged from the LP compressor 24 or the HPcompressor 26.

FIG. 2 is a perspective view of an example of an engine componentillustrated as an airfoil 90, a platform 92, and a dovetail 94, whichcan be a rotating blade 68, as shown in FIG. 1 . Alternatively, it iscontemplated that the airfoil 90 can be a stationary vane, such as thevane 72 of FIG. 1 , while any suitable engine component is contemplated.The airfoil 90 includes a tip 96 and a root 98, defining a span-wisedirection there between. Additionally, the airfoil 90 includes an outerwall 100. A pressure side 104 and a suction side 106 are defined by theairfoil shape of the outer wall 100. The airfoil 90 further includes aleading edge 108 and a trailing edge 110, defining a chord-wisedirection.

The airfoil 90 mounts to the platform 92 at the root 98. The platform 92is shown in section, but can be formed as an annular band for mounting aplurality of airfoils 90. The airfoil 90 can fasten to the platform 92,such as welding or mechanical fastening, or can be integral with theplatform 92 in non-limiting examples. A platform wall 102 defines theplatform 92.

A set of cooling holes 112 can be formed in any wall of the componentincluding the outer wall 100 or the platform wall 102 as illustrated.The set of cooling holes 112 can be referencing a single cooling hole ormultiple cooling holes. The set of cooling holes 112 can be located byway of non-limiting example, proximate the leading edge 108, thetrailing edge 110 and be located in the platform 92 on the pressure side104 of the airfoil 90. It should be understood that the locations of theset of cooling holes 112 is for illustrative purposes only and not meanto be limiting.

The dovetail 94 couples to the platform 92 opposite of the airfoil 90,and can be configured to mount to the disk 71, or rotor 51 of the engine10 (FIG. 1 ), for example. In one alternative example, the platform 92can be formed as part of the dovetail 94. The dovetail 94 can includeone or more inlet passages 114, illustrated as three inlet passages 114.It is contemplated that the inlet passages 114 are fluidly coupled tothe set of cooling holes 112 to provide a cooling fluid flow (C) forcooling the platform 92. In another non-limiting example, the inletpassages 114 can provide the cooling fluid flow (C) to an interior ofthe airfoil 90 for cooling of the airfoil 90. It should be appreciatedthat the dovetail 94 is shown in cross-section, such that the inletpassages 114 are housed within the body of the dovetail 94.

It should be understood that while the description herein is related toan airfoil, it can have equal applicability in other engine componentsrequiring cooling via cooling holes such as film cooling. One or more ofthe engine components of the engine 10 includes a film-cooled substrate,or wall, in which a film cooling hole, or hole, of the disclosurefurther herein may be provided. Some non-limiting examples of the enginecomponent having a wall can include blades, vanes or nozzles, acombustor deflector, combustor liner, or a shroud assembly. Othernon-limiting examples where film cooling is used include turbinetransition ducts and exhaust nozzles.

FIG. 3 is an enlarged portion III taken from FIG. 2 of the set ofcooling holes 112 located in the platform wall 102. While any number ofcooling holes 112 are contemplated, thirteen cooling holes 112 are shownfor illustrative purposes only and are not meant to be limiting. Each ofthe cooling holes terminates in an outlet 120 along a heated surface 122of the platform wall 102. The heated surface 122 faces a hot gas fluidflow (H) during operation.

The outlet 120 has a modified shape 124 at the heated surface 122. Themodified shape 124 can include multiple sections, by way of non-limitingexample an expanding section 126, a constant section 128, and acontracting section 130.

FIG. 4 is an enlarged top down view of at least one cooling hole 112representative of any of the multiple cooling holes from FIG. 3 . The atleast one cooling hole 112 can include a connecting passage 132extending between an inlet 134 and the outlet 120 to define a downstreamflow direction from the inlet 134 to the outlet 120. The inlet 134 canbe fluidly coupled to any source of the cooling fluid (C) including butnot limited to interior cooling circuits and/or cooling conduits. Theconnecting passage 132 can at least partially define the at least onecooling hole 112 through which the cooling fluid (C) can flow. The inlet134 can define a diameter (D). It should be understood that if thecross-sectional area of the inlet is of a non-circular shape thediameter (D) is the diameter of a circular cross-sectional area havingthe same area as the non-circular shape.

The connecting passage 132 can further include a metering section 136having a circular cross section, though it could have anycross-sectional shape. The metering section 136 can be provided at ornear the inlet 134, and extend along the connecting passage 132 whilemaintaining a constant cross-sectional area (CA). The metering section136 defines the smallest, or minimum cross-sectional area (CA) of theconnecting passage 132. It is further contemplated that the meteringsection 136 defines the inlet 134 without extending into the connectingpassage 132 at all. It is also contemplated that the metering section136 has no length and is any other location where the cross-sectionalarea (CA) is the smallest within the connecting passage 132. Themetering section 136 can extend a metering length (L_(m)) of between 0and 1 times the diameter. In an aspect of the disclosure herein themetering section 136 have a metering length (L_(m)) of 0.5D. Themetering section 136 is for metering of the mass flow rate of thecooling fluid flow (C).

In another aspect of the disclosure herein, the connecting passage 132can define an increasing cross-sectional area (CA2) where at least aportion of the increasing cross-sectional area (CA2) defines a diffusingsection 138 having a maximum cross-sectional area of the passage. Insome implementations the cross-sectional area (CA2) is continuouslyincreasing as illustrated. In yet another implementation thecross-sectional area (CA2) can vary along the extent of the connectingpassage 132 to define multiple metering and diffusing sections. Theconnecting passage 132 can be defined by sidewalls 139 that extend at aside angle α of between 5 and 10 degrees from the metering section 136toward the outlet 120 to further define the diffusing section. In anaspect of the disclosure herein the side angle α is 7 degrees.

The outlet 120 extends between an upstream end 140 and a downstream end142 with respect to the hot gas fluid flow (H). The diffusing section138 can terminate at the expansion section 126 of the outlet 120. Theexpansion section 126 can extend between the upstream end 140 and afirst boundary line 144 delineating a beginning of the constant section128. The expansion section 126 defines an increasing width (W1) of theoutlet 120 increasing in the downstream direction from the upstream end140 to the first boundary line 144. In some implementations theincreasing width (W1) is continuously increasing as illustrated. It isfurther contemplated that the expansion section 126 of the outlet 120expands at the same angle α as sidewalls 139 for the diffusing section138.

The constant section 128 extends in the downstream direction from thefirst boundary line 144 to a second boundary line 146 delineating an endof the constant section 128. The constant section 128 defines a constantwidth (W2) maintained along a length (L) between the first and secondboundary lines 144, 146. It is contemplated that the increasing width(W1) equals the constant width (W2) at the first boundary line 144.

The contraction section 130 can extend between the second boundary line146 and the downstream end 142 of the outlet 120. The contractionsection 130 defines a decreasing width (W3) of the outlet 120 decreasingin the downstream direction from the second boundary line 146 to thedownstream end 142. In some implementations the decreasing width (W3) iscontinuously decreasing as illustrated.

FIG. 5 is a schematic sectional view of the at least one cooling hole112 taken along V-V in FIG. 3 and extending through the platform wall102. The platform wall 102 includes the heated surface 122 facing thehot gas fluid flow (H) and a cooled surface 148 facing the cooling fluid(C). It can more clearly be seen that the inlet 134 for the at least onecooling hole 112 is provided on the cooled surface 148 and the outlet120 is provided on the heated surface 122. It should be understood thatthe platform wall 102 can be any substrate within the engine 10including but not limited to the outer wall 100, a tip wall, or acombustion liner wall. Materials used to form the substrate include, butare not limited to, steel, refractory metals such as titanium, orsuperalloys based on nickel, cobalt, or iron, and ceramic matrixcomposites. The superalloys can include those in equiaxed, directionallysolidified, and crystal structures. The substrate can be formed by, innon-limiting examples, 3D printing, investment casting, or stamping.

It is noted that although the platform wall 102 is shown as beinggenerally planar in FIG. 5 , it should be understood that that theplatform wall 102 can be curved for many engine components. Whether theplatform wall 102 is planar or curved local to the at least one coolinghole 112, the heated and cooled surfaces 122, 148 can be parallel,especially on a local basis, to each other as shown herein, or can liein non-parallel planes.

As is more clearly illustrated in FIG. 5 , the connecting passage 132can define a metered centerline (CL_(m)) along which the metering length(L_(m)) of the metering section 136 is measured. As is illustrated by anextension of the metered centerline (CL_(m)) to the heated surface 122,an entrance angle β is formed therebetween. It should be understood thatthe entrance angle β can also be measured between the cooled surface 148and the metered centerline (CL_(m)). The entrance angle β is between 20and 40 degrees. In an aspect of the disclosure herein the entrance angleβ is 30 degrees.

As the diffusing section 138 extends from the metering section 136 tothe outlet 120, the connecting passage 132 can define a diffusedcenterline (CL_(d)) along which a diffused length (La) is measured. Thediffused centerline (CL_(d)) can be curvilinear and transition betweenan orientation with the entrance angle β to a layback or exit angle S.The exit angle δ is less than the entrance angle β. In an aspect of thedisclosure herein the exit angle is 10 degrees. Together the diffusedcenterline (CL_(d)) and the metered centerline (CL_(m)) define acontinuous passage centerline for the connecting passage 132.

The at least one cooling hole 112 provides fluid communication betweenthe cooling fluid (C) supply and an exterior of the platform 92. Duringoperation, the cooling fluid flow (C) can be supplied via the inletpassages 114 and exhausted from the set of cooling holes 112 as a thinlayer or film of cool air along the heated surface 122. While only onecooling hole is shown in FIG. 5 , it is understood that thecross-sectional view can represent any one of or all of the coolingholes in the set of cooling holes 112 of FIG. 3 .

It is contemplated that the set of cooling holes 112 as described hereinare additively manufactured. An additive manufacturing (AM) process iswhere a component is built layer-by-layer by successive deposition ofmaterial. AM is an appropriate name to describe the technologies thatbuild 3D objects by adding layer-upon-layer of material, whether thematerial is plastic or metal. AM technologies can utilize a computer, 3Dmodeling software (Computer Aided Design or CAD), machine equipment, andlayering material. Once a CAD sketch is produced, the AM equipment canread in data from the CAD file and lay down or add successive layers ofliquid, powder, sheet material or other material, in a layer-upon-layerfashion to fabricate a 3D object. It should be understood that the term“additive manufacturing” encompasses many technologies including subsetslike 3D Printing, Rapid Prototyping (RP), Direct Digital Manufacturing(DDM), layered manufacturing and additive fabrication. Non-limitingexamples of additive manufacturing that can be utilized to form anadditively-manufactured component include powder bed fusion, vatphotopolymerization, binder jetting, material extrusion, directed energydeposition, material jetting, or sheet lamination.

It is contemplated that the diffusing section 138 terminates in a hood164 and the wall 102 at the heated surface 122 covers at least a portionof the diffusing section 138 prior to the outlet 120. A thickness of thehood 164 can be less than or equal to 0.02 inches before a thermalbarrier coating (TBC) is applied and less than 0.05 inches after anapplication of TBC. Though illustrated as having a thickness at theupstream end 140, it is contemplated that the hood 164 tapers to zerothickness at the upstream end 140.

FIG. 6 illustrates a patterned layout 150 for the set of cooling holes112. Some numbers from previous figures have been eliminated forclarity. The modified shape 124 enables a pattern in which multipleoutlets 120 are stacked close together and in-line along dashed line 152as illustrated. More particularly, both the inlet 134 and the constantsection 128 of the outlet 120 are in-line along dashed line 152. Dashedlines 154 a, 154 b extend from the sidewalls 139 a, 139 b of exemplaryoutlets 120 a and 120 b to illustrate where the outlet 120 can extend towith the constant section 128 eliminated. Truncating a typical diffusershape of an outlet to form the modified shape 124 enables the formationof tightly spaced and an increasing number of cooling holes 112 in agiven space along platform wall 102.

The set of cooling holes 112 can include exemplary cooling holes 112 a,112 b. An outlet 120 b of cooling hole 112 b can be located above aninlet 134 a of cooling hole 112 b. In other words, a geometric center156 of the inlet 134 a and the outlet 120 b can be in-line with eachother. In this manner outlet 120 b is located at the heated surface 122in a same location as the inlet 134 a is spaced from the heated surface122 within the platform wall 102. Therefore, the set of cooling holes112 as described herein can be stacked, layered, and tightly spaced toincrease cooling film effectiveness along the heated surface 122.

A method for forming the set of cooling holes 112 with the modifiedoutlet shape 124 can include forming the set of cooling holes 112 suchthat the inlet 134 is located on a first surface, by way of non-limitingexample the cooled surface 148 described herein and the outlet 120 isformed on a second surface, by way of non-limiting example the heatedsurface 122 as described herein. The method includes forming theconnecting passage 132 to connect the inlet 134 to the outlet 120, byway of non-limiting example using methods already described herein. Theoutlet 120 is formed with the modified outlet shape 124 having theexpansion section 126 and the constant section 128 downstream from theexpansion section 126. The method can further include forming themodified shape 124 with the contraction section 130 located downstreamfrom the constant section 128.

The method can further include determining a patterned layout 150 forthe set of cooling holes comprising a first line 152 a and a second line152 b parallel to the first line 152 a. The set of cooling holes 112 caninclude a first pair of cooling holes 112 a having a first pair ofinlets 134 a in line with the first line 152 a. A first pair of outlets120 a are in line with the second line 152 b.

The method can further include forming a second pair of cooling holes112 b where a second pair of outlets 120 b are formed above the firstpair of inlets 134 a with respect to the cooled surface 148. In otherwords while the second pair of outlets 120 b are formed in the heatedsurface 122, the inlets are formed interiorly of the heated surface 122in the cooled surface 148 and in-line along a geometric center 156 ofthe first pair of inlets 134 a.

Truncating a typical outlet shape to form the modified shape 124 enablesthe formation of tightly spaced and an increasing number of coolingholes 112 in a given space along platform wall 102. The set of coolingholes 112 can be layered where the inlet 134 is located beneath theoutlet 120 of an adjacent cooling hole 112. Therefore the set of coolingholes 112 as described herein can be stacked, layered, and tightlyspaced to increase cooling film effectiveness along the heated surface122.

Turning to FIG. 7 , a cooling hole 212 is illustrated in cross-sectionaccording to another aspect of the disclosure herein. The cooling hole212 is similar to the at least one cooling hole 112 therefore, likeparts will be identified with like numbers increased by 100, with itbeing understood that the description of the like parts of the at leastone cooling hole 112 applies to the cooling hole 212 unless otherwisenoted.

The cooling hole 212 includes all aspects of the at least one coolinghole 112 already described herein and additionally includes a turn 260,or step down feature. Instead of transitioning from the entrance angle βto the exit angle δ gradually, the turn 260 located at or near an outlet220 of the at least one cooling hole 112 enables an abrupt change inorientation. To transition between an entrance angle β of between 20 and40 degrees to an exit angle δ of below 20 degrees, by way ofnon-limiting example a 10 degree exit angle, the abrupt change isdefined by the turn 260 immediately upstream from the outlet 220. Byabrupt, the turn 260 is illustrated as a step down feature rather thanramped or gradual. Both a metering section 236 and a diffusing section238 of the at least one cooling hole 212 extend through a wall 202 of anengine component at the same angled orientation. The diffusing section238 terminates in the turn 260 to define a transition portion 262 wherethe wall 202 at the heated surface 222 forms a hood 264 covering atleast a portion of the diffusing section 238 prior to the outlet 220.

In an aspect of the disclosure herein the method can further includeforming the transition portion 262 defining the turn 260 in thediffusing section 238 and upstream from the outlet 220. The coolingfluid (C) fluid as described herein dips 266 or moves suddenly inwardbefore continuing on a more gradual exit angle S. This can enable nearwall cooling at or near the heated surface 222 immediately upstream fromthe outlet 220.

Turning to FIG. 8 , a cooling hole 312 having a modified diffusion shape324 is illustrated in a top down view according to another aspect of thedisclosure herein. The cooling hole 312 is similar to the at least onecooling hole 112 therefore, like parts will be identified with likenumbers increased by 200, with it being understood that the descriptionof the like parts of the at least one cooling hole 112 applies to thecooling hole 312 unless otherwise noted.

The cooling hole 312 terminates in an outlet 320 having multiplesections including an expansion section 326, a constant section 326, anda contraction section 330 defining a modified diffusion shape 324. Themodified diffusion shape 324 includes all aspects of the modified shape124 already described herein. Additionally, the modified diffusion shape324 includes a second expansion section 326 b having an increasing widthW4 and located downstream from the constant section 328 and upstreamfrom the contraction section 330. The second expansion section 326 b canextend between a second boundary line 346 delineating an end of theconstant section 328 and a third boundary line 347 delineating an end ofthe second expansion section 326 b. It is contemplated that a maximumwidth of both the second expansion section 326 b and the contractionsection 330 are equal to each other (W4=W3) at the third boundary line347.

In an aspect of the disclosure herein the method can further includeforming a second expansion section 326 b downstream from the constantsection 328 and upstream from the contraction section 330 to define themodified diffusion shape 324.

Turning to FIG. 9 , an additional patterned layout 350 for the set ofcooling holes 312. In an aspect of the disclosure herein the modifieddiffusion shape 324 enables a staggered pattern where an inlet 334 foreach of the cooling holes 112 is in-line with an angled dashed line 352as illustrated. The angled dashed line 352 is angled with respect to thehot gas fluid flow (H) at some angle θ. Some numbers from previousfigures have been eliminated for clarity. The modified diffusion shape324 enables a pattern in which multiple outlets 320 are staggered closetogether. Dashed lines 354 a, 354 b extend from sidewalls 339 a, 339 bof exemplary outlets 320 a and 320 b to illustrate where the outlet 320can extend to with the constant section 328 eliminated. Truncating atypical diffuser shape of an outlet to form the modified diffusion shape324 enables the formation of tightly spaced and an increasing number ofcooling holes 312 in a given space along platform wall 302.

As is already described herein, the set of cooling holes 312 can belayered where the inlet 334 is located beneath the outlet 320 of anadjacent cooling hole 312. Therefore the set of cooling holes 312 asdescribed herein can be stacked, layered, and tightly spaced to increasecooling film effectiveness along the heated surface 322.

It is further contemplated that the method can include determining apatterned layout for the set of cooling holes 312 and forming multiplecooling holes 312 with multiple outlets 320 proximate each other suchthat the inlet 334 for each of the multiple cooling holes 312 is in-linealong the angled line 352.

The outlet shapes as described herein focus and streamline cooling fluidto create a film along the outer wall of an engine component. Thepatterned and staggered layouts provide uniform cooling to the outerwall. The constant section in particular of the outlet shape asdescribed herein enables the streamlining of the cooling fluid.

Turbine cooling is important in next generation architecture whichincludes ever increasing temperatures. Current cooling technology needsto expand to the continued increase in core temperature of the enginethat comes with more efficient engine design. Optimizing cooling at thesurface of engine components by designing cooling hole geometry thatstreamlines the cooling fluid upon exhausting from the set of coolingholes described herein improves the entire engine performance.

It should be appreciated that application of the disclosed design is notlimited to turbine engines with fan and booster sections, but isapplicable to turbojets and turbo engines as well.

This written description uses examples to illustrate the disclosure asdiscussed herein, including the best mode, and also to enable any personskilled in the art to practice the disclosure as discussed herein,including making and using any devices or systems and performing anyincorporated methods. The patentable scope of the disclosure asdiscussed herein is defined by the claims, and may include otherexamples that occur to those skilled in the art. Such other examples areintended to be within the scope of the claims if they have structuralelements that do not differ from the literal language of the claims, orif they include equivalent structural elements with insubstantialdifferences from the literal languages of the claims.

What is claimed is:
 1. A component for a turbine engine which generatesa hot gas fluid flow, and provides a cooling fluid flow, comprising: awall separating the hot gas fluid flow from the cooling fluid flow andhaving a heated surface along which the hot gas fluid flow flows and acooled surface facing the cooling fluid flow; a set of cooling holescomprising at least a first cooling hole and a second cooling holelocated downstream from the first cooling hole, the first cooling holecomprising a first inlet located at the cooled surface and a firstoutlet located at the heated surface, the second cooling hole comprisinga second inlet located at the cooled surface beneath the first outletand a second outlet located at the heated surface, where the firstoutlet and the second outlet each define a modified outlet shape having:at least one expansion section having an increasing width, a contractionsection downstream of the at least one expansion section and having adecreasing width, and a constant section upstream of the contractionsection.
 2. The component of claim 1, wherein a geometric center of thefirst outlet is in line with a geometric center of the second inlet. 3.The component of claim 1, wherein each of the first and second coolingholes include at least one connecting passage extending fromcorresponding first and second inlets to corresponding first and secondoutlets, each of the connecting passages defining a passage centerlineand a downstream flow direction from the corresponding first and secondinlets to the corresponding first and second outlets.
 4. The componentof claim 3, wherein the at least one connecting passage comprises ametering section fluidly coupled to at least one of the first and secondinlet and a diffusing section, downstream of the metering section, andfluidly coupling the metering section to at least one of the first andsecond outlet.
 5. The component of claim 4, wherein the diffusingsection terminates in a hood defined at least in part by the wall andcovering at least a portion of the diffusing section prior to thecorresponding first and second outlet.
 6. The component of claim 4,wherein the passage centerline at the diffusing section forms an exitangle with the heated surface that is less than an entrance angle withthe heated surface formed by the passage centerline of the meteringsection.
 7. The component of claim 1, wherein the at least one expansionsection is multiple expansion sections including a first expansionsection upstream of the constant section and a second expansion sectionlocated downstream of the constant section.
 8. The component of claim 7,wherein both second expansion sections, associated with each of thefirst outlet and the second outlet, each comprise a continuouslyincreasing width.
 9. A method for forming the set of cooling holes ofthe component of claim 1 the method comprising: forming the set ofcooling holes such that the first and second inlets are located on thecooled surface and the first and second outlets are located on theheated surface and a geometric center of the first outlet is in linewith a geometric center of the first inlet; forming a connecting passageto connect each of the first and second inlets to the correspondingfirst and second outlets; and forming the first and second outlets eachwith the modified outlet shape.
 10. The method of claim 9, furthercomprising forming a patterned layout for the set of cooling holescomprising a first line and a second line parallel to the first line.11. The method of claim 10, further comprising forming the patternedlayout wherein the set of cooling holes includes a first pair of coolingholes and a first pair of inlets are in line with the first line and afirst pair of outlets are in line with the second line.
 12. The methodof claim 11, wherein the first line and the second line are angled withrespect to a flow direction.
 13. A component for a turbine engine whichgenerates a hot gas fluid flow, and provides a cooling fluid flow,comprising: a wall separating the hot gas fluid flow from the coolingfluid flow and having a heated surface along which the hot gas fluidflow flows and a cooled surface facing the cooling fluid flow; a firstpair of cooling holes, each cooling hole comprising a first inletlocated at the cooled surface and a first outlet located at the heatedsurface, the first outlet comprising a modified outlet shape including aconstant section, a second pair of cooling holes located downstream fromthe first pair of cooling holes, each cooling hole comprising a secondinlet located at the cooled surface beneath the first outlet and asecond outlet located at the heated surface, the second outletcomprising the modified outlet shape; wherein the constant sectionenables tight spacing of the first and second pair of cooling holes withrespect to each other; and wherein the first and second pair of coolingholes together form a patterned layout.
 14. The component of claim 13,wherein a geometric center of the first inlets of the first pair ofcooling holes are in line with each other and a geometric center of thesecond inlets of the second pair of cooling holes are also in line witheach other.
 15. The component of claim 13, wherein the modified shapefurther comprises at least one expansion section having an increasingwidth.
 16. The component of claim 15, wherein the modified shape furthercomprises a contraction section downstream of the at least one expansionsection and having a decreasing width.
 17. The component of claim 16,wherein the constant section is upstream of the contraction section. 18.The component of claim 13, wherein the component is a combustor and thewall forms a combustor liner.